Production of bioethanol from sweet sorghum: A review

The consumption of bioethanol as biofule may reduce greenhouse gases, gasoline imports. Also it can be replaced with lead or MTBE (Methyl tert-butyl ether) that are air and underground water pollutants, respectively. Plants are the best choice for meeting the projected bioethanol demands. For this scope, a comparative analysis of the technological options using different feedstocks should be performed. Our research and other studies indicate that sweet sorghum can be used as a feedstock for ethanol production under hot and dry climatic conditions. Because, it has higher tolerance to salt and drought comparing to sugarcane and corn that are currently used for biofuel production in the world. In addition, high carbohydrates content of sweet sorghum stalk are similar to sugarcane but its water and fertilizer requirements are much lower than sugarcane. Also, sugarcane is not a salt tolerant plant. On the other hand, high fermentable sugar content in sweet sorghum stalk makes it to be more suitable for fermentation to ethanol. Therefore, it is suggested to plant sweet sorghum for biofule production in hot and dry countries to solve problems such as increasing the octane of gasoline and to reduce greenhouse gases and gasoline imports.   Key words: Sweet sorghum, carbohydrate, bioethanol, biofuel.